Week 6 Powders 1 Flashcards
What 2 things do we need to know to make a dosage form
physical and chemical properties
What is an api
active pharmaceutical ingredient
what is an excipient
inert ingredient which gives functionality to the dosage form
What 5 assumptions do we make about an API
Penny Bought Detective Analysis at an Acceptable Rate
API pure
API produced in bulk for pre formulation
Detect and identify any impurities and degradation products
Qualitative and Quantitative analysis
BP specification will include acceptable limits on any impurities
What is the purpose of pre formulation
Looking to understand the nature of the API
How it behaves alone
How it interacts with excipients
What chemical properties should be taken into the account of the API
Chemical Stability
Solubility
Crystal form
Hygroscopicity
Particle size
Flow
Segregation
What does knowledge of the chemical stability provide
Gives us information on
Temperature which affects sterilisation pH Moisture Oxygen how to manufacture Light which affects storage / packaging
What does accelerated stability include
use of high temperatures and humidity
What must an api be
they must have some aqueous solubility for therapeutic effect
what does a poor solubility lead to
erratic or incomplete absorption
what should solubility be checked at
over a range of temperatures and pH
How can we atler the solubility of an API
Salt Forms
What are the two categories of solid
Crystaline
Amorphous
What is an amorphous api
an api with no regular molecular lattice arrangement
what is a polymorph
a different crystal packing arrangement in a crystal
what is the consequence of a polymorph
a polymorph has different physicochemical and mechanical properties
solubility
stabilities
dissolution rates
melting points etc
Why is it vital that the polymorphic form of the APi is known and consistent
due to physicochemical and mechanical properties being vital in formulation
it could mean that there would be unexpected behaviour and potentially big harm to the patient
what is hygroscopicity
degree of moisture uptake by an API
what can poor hygroscopicity cause
swelling / particle size increase
instability
degradation
microbial spoilage
What are the 4 factors that affect processing
particle size and shape
bulk density
powder flow
compressibility
why do smaller particles have faster dissolution rate for the same volume or mass
they have a larger surface area meaning that particle size affects the dissolution rate
what is dissolution rate
The dissolution rate is defined as the rate or speed at which a drug substance dissolves in a medium.
why is low bulk density bad
a low bulk density means a large volume so a large tablet thus inconvenient
why is a range of bulk density bad
different tablet weights
what is flow a key attribute of
granules and powders
why is flow important
achieving uniformity of dosage and weight
what state should a powder flow at to be considered for easy industrial production.
liquids
what can poor flow cause
capping / lamination of tablets
how can we change flow
change particle size
reduce inter particle forces
add excipients
change manufacturing equipment
To make tablets what do you need
API and excipient particles to bind together via compaction
What is plastic materials
deform by changing shape (plastic flow)
on compression doesnt get any new surfaces forming
plastic materials bond develop with time so need to dwell in tablet die longer
Elastic materials
recover shape elastically after compression removed
bonding weak tablet will break by capping or lamination
brittle materials
Fragment on compression
exposes new surfaces
can lead to high friability
what is friability
the tendency of a solid substance to break into smaller pieces under duress or contact, especially by rubbing.
The opposite of friable is indurate
why is sticking important to measure
if powder is sticky will adhere to punc hand die and can lead to variable tablet weights
